Leetcode：Search a 2D Matrix 搜索二維矩陣

題目描述

 

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:

 

• Integers in each row are sorted from left to right.
• The first integer of each row is greater than the last integer of the previous row.

 

For example,

Consider the following matrix:

[
  [1,   3,  5,  7],
  [10, 11, 16, 20],
  [23, 30, 34, 50]
]

Given target =3, returntrue.

public class Solution {
    public boolean searchMatrix(int[][] matrix, int target) {
        int lena=matrix.length;
        if(lena==0)
            return false;
        for(int i=0;i<lena;i++)
            for(int j=0;j<matrix[0].length;j++)
            {
                if(matrix[i][j]==target)
                    return true;
            }
        return false;
        
    }
}